Hemispherical resonator gyroscope(HRG) is a kind of angle rate sensor with high precision, high reliability, and small size weight and power(SWaP). HRG innovative approach is a real game changer in high end navigation, which may change the territory of inertial navigation industry. In this paper, the current advances of HRG are reviewed, the research gap between home and abroad is analyzed. The key technology of HRG is summarized, and the technologies of the precision processing, chemical etching, frequency balancing, film deposition, assembling, electronics and control, error compensation, etc. are emphasized. In the end, the developing trends of HRG technology and market are discussed.